JPH0674027B2 - Anti-skidding control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an anti-skid control device, and more particularly to such a device that prevents hydraulic pressure fluctuations during anti-skid control from being transmitted to a brake pedal.

[Conventional technology]

In general, the anti-skidding control device separates the pipe (pressurizing pipe) for transmitting the normal brake hydraulic pressure from the pipe of the normal system to reduce or pressurize the brake hydraulic pressure when a wheel locking tendency occurs. It is usually configured by connecting piping (pressure reducing piping), and the pressure reducing piping system is
There are cases where it is the same hydraulic system as the normal brake system and cases where it is an independent hydraulic system.

In any of these cases, it is conceivable that when the hydraulic pressure fluctuation of the brake hydraulic pressure during the anti-skidding control is transmitted to the brake pedal, the brake pedal is rattled, which causes a feeling that is not preferable in driving operation.

Therefore, a pressure accumulator is provided to prevent such fluctuations in brake hydraulic pressure from being transmitted to the brake pedal side, and the accumulated pressure oil of this pressure accumulator is used to pressurize the brake hydraulic pressure, and the master cylinder of the normal brake system is used. There is also proposed an anti-skidding control device in which the connection between the brake device and the brake device is cut off.

However, even in such a device, if pressure oil on the brake device side is pumped up to the pressure accumulator by exceeding the capacity of the pressure accumulator, the amount exceeding this capacity limit is used to prevent damage to the accumulator. However, if the anti-skidding control system and the normal brake system are the same hydraulic system, this hydraulic pressure must be released to the master cylinder side, which hinders complete prevention of the brake pedal. Becomes

Such a problem can be solved by, for example, sufficiently increasing the capacity of the pressure accumulator, but it goes without saying that such an increase in the size of the pressure accumulator is not preferable, and further, in a necessary and sufficient range that satisfies the characteristics of the anti-skid control. If the capacity of the pressure accumulator is limited to achieve miniaturization, the problem may occur more frequently.

[Problems to be Solved by the Invention]

The present invention has been made from such a viewpoint, and an object thereof is to consider the operation of the anti-skid control, realize the downsizing of the pressure accumulator, and, at the same time, to prevent the possibility of scratching that may be transmitted to the brake pedal. It is in the place where I tried to solve it.

[Means for Solving the Problems]

Therefore, the feature of the anti-skidding control device according to the present invention made to realize such an object is that an electronic control device for anti-skid control and a brake hydraulic pressure transmission path of a normal brake system connecting the master cylinder and the brake device are hydraulically operated. A gate valve that shuts off by operation, and a hydraulic control device that performs hydraulic control of reducing or pressurizing the brake hydraulic pressure on the side of the brake device downstream of the gate valve or further holding the hydraulic pressure as needed,
This hydraulic control device receives a signal from the electronic control device as an input and holds a brake hydraulic pressure, and a hold valve that closes a normally open flow passage for pressure reduction and a pressure reducing valve that opens a normally open flow passage for pressure reduction. And a pump for pumping pressure oil to reduce the pressure with the operation of the solenoid valve device,
A pressure accumulator that stores the pumped pressure oil from this pump and returns it between the gate valve and the hold valve is configured, and the gate valve is a pressure pumped by the accumulator rather than the brake oil pressure downstream of the hold valve. In an anti-skid control device configured to hydraulically close the normally open flow path when the oil is large, the pressure accumulator is a pressure accumulation piston that moves by compressing a pressure accumulation spring with the pressure oil pumped from the pump,
A stroke switch for detecting a movement of the pressure accumulating piston above a certain value, and a signal from the stroke switch is input to the electronic control unit, and an output is connected to the pump, and a constant pressure accumulator is provided. This is where a pump deactivation circuit is provided to deactivate the pump when moving above the specified value.

[Action]

According to the above configuration, by detecting the constant value movement of the pressure accumulating piston of the stroke switch, the operation of the pump is canceled so as not to cause any further movement.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings in comparison with a conventional example.

It should be noted that in contrast to FIGS. 1 (a) and 1 (b) showing the example of the present invention, FIGS. 2 (a) and 2 (b) showing a conventional example show a partial configuration (presence or absence of the relief valve 115 and the stroke switch 14). They have the same structure except that the same members and mechanisms are shown by adding 100 to the reference numerals in FIG.
It was decided to prompt the figure.

In these figures, the main path (brake hydraulic pressure pressurizing pipe) for transmitting brake hydraulic pressure from the master cylinder M / C.
1, 2, and 3 are connected to the brake device W / C via a normally-open type gate valve device 4 and a hold valve 5 which are hydraulically operated in the middle, and are connected to the upstream side of the hold valve 5 (master cylinder side). ) 1, 2 form an input system Ai and communicate with the input oil chamber A of the gate valve device 4, and the main path 2 between the output oil chamber B of the gate valve device 4 and the hold valve 5 forms an intermediate oil chamber Am. is doing. The downstream side (brake device side) 3 of the hold valve 5 of the main path constitutes an output system A ₀ .

A bypass path (brake hydraulic pressure reducing pipe) 7 is connected between the output system A ₀ which is the main path 3 and the intermediate oil chamber Am (the output oil chamber B of the gate valve device 4 and the main path 2 in the illustrated example). In the present example, the main path output system A ₀ is provided with a normally closed pressure reducing valve 6, a reservoir 8, a pump 9, a pressure accumulator 11, and a check valve 12 in this order in the middle of the bypass path 7. When the pressure oil flows into the reservoir 8 due to the opening of the pressure reducing valve 6,
This pressure oil is pumped to the pressure accumulator 11 and the check valve
It is provided so as to return to the intermediate oil chamber Am via 12.

In the above configuration, the hold valve 5 and the pressure reducing valve 6
Is provided as an electromagnetic switching valve, and the former hold valve is opened by a signal S ₁ output from an electronic control circuit (not shown) for anti-skidding control (that is, a signal instructing to stop or increase the brake hydraulic pressure or hold the brake hydraulic pressure). A switching operation of → close is performed, and the latter pressure reducing valve is configured to generate the switching operation of close → open by a signal S ₂ instructing a decrease in brake hydraulic pressure.

The reservoir mechanism 8 and the pump 9 may be known ones,
The pump 9 pumps up in synchronism with the closing / opening of the pressure reducing valve 6. The pump 9 is driven by a motor 10.

With the above-described configuration, the control for increasing and decreasing the brake hydraulic pressure is normally performed by the gate valve device 4 and the hold valve 5.
Is normally open, and the pressure reducing valve 6 is normally closed, so the hydraulic pressure generated in the master cylinder M / C is transmitted to the brake device W / C as it is, and when the brake is released, it remains as it is.
Will return to M / C. During the anti-skid control, the hold valve 5 is closed and closed, and the pressure reducing valve 6 is closed and opened, so that the pressure oil in the brake device W / C is pumped up from the bypass passage 7 to the intermediate oil chamber Am, and then the pressure reducing valve 6 is opened. → By returning to closed and opening and closing the hold valve 5 appropriately, the brake hydraulic pressure can be raised again or held.

The opening / closing switching control of the hold valve 5 and the pressure reducing valve 6 performed by an electronic control circuit is performed by using a signal from a speed sensor for detecting wheel rotation speed and a brake switch (neither is shown) as input. The circuit is carried out by deciding the necessary brake hydraulic pressure reduction and pressurization depending on the wheel speed drop and the recovery change state. Specifically, for example, the proposed anti-skid control method can be used. Further, the gate valve device 4 is for preventing fluctuations in the brake hydraulic pressure reduction and pressurization in the brake device from being transmitted to the brake pedal side. Specifically, in normal times, the main path input diameter Ai is always maintained. The open state is maintained to allow smooth transmission and return of pressure oil, and during anti-skid control, the input system Ai mechanically responds to the differential pressure generated between the main path input system Ai and output system A _0. The intermediate oil chamber Am is pressure-isolated from the master cylinder M / C side, so that the influence of the pressure change when the brake hydraulic pressure is lowered or raised is not transmitted to the master cylinder at all.

The structure of the gate valve device 4 in this example has a balance piston 4a in the body, and the movement of the balance piston 4a allows the shutoff valve in the room to be switched from the normally open state to the closed state. The input oil chamber A connected to the master cylinder side in the valve and the output oil chamber B connected to the hold valve 5 side can be opened and closed.

To describe this in a little more detail, the balance piston accommodating chamber accommodates the balance piston 4a so as to be movable in the axial direction, one end thereof faces the oil chamber C at one end communicating with the main path output system A ₀ , and the other end thereof is the accumulator. It faces the other end oil chamber D to which the hydraulic pressure from 11 is transmitted, and the balance piston 4a is engaged with a lightly loaded set spring 4b and is biased to the limit position on the other end oil chamber D side. In this example, the balance piston
A return valve 13 that allows only the flow of the pressure oil from the oil chamber C to the oil chamber A is built in the inside of 4a. This is for smoothing the return of the pressure oil particularly when the brake is released. belongs to.

Further, in the conventional example shown in FIG. 2, a relief valve 115 that allows the flow of the pressure oil from the oil chamber B to the oil chamber A is provided in the balance piston 4a (or independently of this). This is omitted in the embodiment of the present invention shown in FIG.

When the gate device valve 4 having the balance piston 4a having the above-described configuration is operated in the non-brake state and the normal brake state, the force acting on the balance piston in both axial directions is equal to the spring force of the set spring 4b at the other end oil chamber D. The balance piston 4a is biased to a limit position on the other end oil chamber D side, and the shut-off valve in the gate valve device is in the normally open state shown in the figure. maintain.

On the other hand, during anti-skid control, the main path output system A ₀ is shut off from the intermediate oil chamber Am by opening and closing the hold 5, and the brake oil pressure in the main path output system A ₀ is closed by opening and closing the pressure reducing valve 6. When is lowered, the force in both axial directions acting on the balance piston 4a in the gate valve device 4 becomes equal to the hydraulic pressure Pc, P _D.
Since P _D >> Pc, it becomes large toward the oil chamber C direction once, and the balance piston 4a moves from the rest position to the oil chamber C direction (left direction in the figure), and enters / exits in the gate valve device 4. The output oil chambers A and B are shut off.

Due to this interruption, the intermediate oil chamber Am is pressure-isolated from the master cylinder side by the gate valve device 4, and the pressure oil pumped up through the bypass passage 7 is not transmitted to the master cylinder side in principle, and the brake pedal in the brake pedal is backed up. Will not occur.

However, when the depressurizing operation of the brake hydraulic pressure continues for a longer period of time, there is a risk that the pressure oil will be pumped up by the pump beyond the capacity of the pressure accumulator.
In order to prevent damage to the valve 11, the relief valve 115 in the conventional example shown in FIG. 2 allows pressure oil to escape to the master cylinder M / C side of the main path input system Ai. It is well known that this leads to the occurrence of a scratching phenomenon.

On the other hand, in the embodiment of the present invention, the relief valve 115 is omitted by the characteristic configuration of the pressure accumulator and the deactivation of the pump 9 associated therewith.

The pressure accumulator 11, the pump 9 and the check valve 12 of this example are for accumulating the pressure oil pumped up by the pump 9, and accumulating in the accumulator cylinder 11a accommodating the accumulator chamber 11b communicating with the bypass passage 7. The piston 11c is slidably engaged with the coil spring 11d by pressing the pressure accumulating piston 11c in the direction of decreasing the volume of the pressure accumulating chamber by the coil spring 11d.
It is provided so as to accumulate the pressure oil based on the spring force of.

And in the pressure accumulator of the embodiment of the present invention shown in FIG.
A stroke switch 14 is provided for engaging with the pressure accumulating piston 11c and detecting the constant length stroke when the accumulating piston 11c has made a constant length stroke, and this detection signal is input to a pump operation release circuit of an electronic control unit (not shown). It is getting done. The drive motor 10 of the pump 9 is deactivated by a signal from an electronic control unit (ECU) by detecting the constant length stroke of the pressure accumulating piston 11c.

With the above configuration, in the embodiment of the present invention, pumping of pressure oil exceeding the rated capacity to the pressure accumulator 11 is prevented during anti-skidding control, and thus the relief valve 115 in the conventional example described above is not necessary. It is Natsuta.

In this configuration, the rated capacity of the pressure accumulator 11 can be limited to a range necessary and sufficient for reducing the brake hydraulic pressure during anti-skidding control, and conventionally, considering the capacity of the pressure accumulator to prevent damage and the like. The problem of giving a certain margin was also resolved, and it was possible to obtain a desired drop even when the accumulator was downsized.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, the hydraulic pressure fluctuation | variation in the brake apparatus which has a possibility of being transmitted to a brake pedal is limited to the brake apparatus of a normal brake system, and there exists an advantage that a pedal feeling preferable in driving operation can be obtained, and also the pressure accumulator. The miniaturization is also realized, and the effect is extremely large.

[Brief description of drawings]

FIGS. 1 (a) and 1 (b) show an example of a schematic configuration of an anti-skidding control device according to the present invention.
The figure shows the non-operation, and (b) shows the same operation. Further, FIGS. 2 (a) and 2 (b) show an example of the configuration outline of the conventional anti-skidding control device. FIG. 2 (a) shows the non-operation, and FIG. 2 (b) shows the same operation. 1,2,3,101,102,103 …… Main path 4,104 …… Gate valve device 5,105 …… Hold valve 6,106 …… Decompression valve 6,107 …… Bypass path 8,108 …… Reservoir 9,109 …… Pump 10,110 …… Pump drive motor 11,111 …… Accumulator 12,112 Check valve 13,113 Return valve 14 Stroke switch 115 Relief valve.

Claims (1)

[Claims] 1. An electronic control unit for anti-skid control,
A gate valve that hydraulically shuts off the brake hydraulic pressure transmission path of the normal brake system that connects the master cylinder and the brake device, and depressurizes, pressurizes, or holds the brake hydraulic pressure on the brake device side downstream of this gate valve as necessary. And a hydraulic control device that performs hydraulic control.
Holding a brake oil pressure by inputting a signal from the electronic control unit, a hold valve that closes the normally open flow path for pressure reduction,
Normally open type flow path for pressure reduction A solenoid valve device consisting of a pressure reducing valve for opening a flow path, a pump for pumping pressure oil for the pressure reduction together with the operation of this solenoid valve device, and a pumping pressure oil from this pump. A pressure accumulator that stores and returns between the gate valve and the hold valve is provided, and the gate valve normally opens when the pressure oil pumped by the pressure accumulator is larger than the brake oil pressure downstream of the hold valve. In an anti-skid control device configured to hydraulically close a path, the pressure accumulator is
The electronic control unit includes a pressure accumulating piston that moves by compressing a pressure accumulating spring by pressure oil pumped from the pump, and a stroke switch that detects a movement of the accumulating piston above a certain value. An anti-skid control device comprising a pump deactivating circuit which receives a signal from a switch and whose output is connected to the pump to deactivate the pump when the pressure accumulator moves above a certain value.